Overhaul Of The Cylinder Barrel/Piston Components - Ducati Diavel Workshop Manual

Cylinder/piston assemblies

Overhaul of the cylinder barrel/piston components

Overhauling the cylinder
Check that the walls of the cylinder bore are perfectly smooth. Measure the cylinder bore diameter at 50 mm from the top
face and determine the size class to which it belongs in accordance with the values specified in Sect. 3 -
1.1Cylinder/Piston. Repeat measurement of the diameter at three heights A (10 mm from the upper surface), B (50 mm
from the upper surface) and C (100 mm from the upper surface) and in two direction at 90° between them; check that
the measurements of taper and ovality in the bore fall within the range specified in Sect. 3 - 1.1, Cylinder/Piston.
In the event of damage or excessive wear the barrel must be renewed as it has a silicon carbide coating (which provides
the cylinder walls with excellent anti-friction and anti-wear properties) and therefore cannot be rebored.
The cylinder barrels are marked with letters (stamped between two oil return ways) indicating their size class.
Always match cylinders with pistons from the same size class.
Overhaul of the piston
Clean the piston crown and piston ring grooves, removing any carbon deposits.
Inspect the piston and check its dimensions carefully: there must be no signs of scuffing, scoring, cracks, or other
damage.
The piston diameter must be measured at 7.5 mm up from the bottom of the skirt and in perpendicular direction to the
pin axis.
The pistons must always be renewed as a pair.